As if this week wasn't active enough, the next couple of days will see Tropical Storm (potentially Hurricane) Karen making landfall on the northern Gulf Coast, a major severe weather outbreak across Iowa and southern Minnesota, and the first major blizzard of the year in the upper Plains.
The first powerful low pressure system of the fall season is getting ready to make its way across the central Plains beginning tomorrow. This system will serve as the focal point for all of the major weather the country will experience over the next couple of days.
The three main features we're watching include:
1) A major severe weather outbreak expected to occur over parts of the upper Midwest tomorrow, centered over northwestern Iowa and southern Minnesota.
2) Tropical Storm Karen (which is expected to become a Hurricane) getting ready to make landfall on the northern Gulf Coast near Mobile, Alabama.
3) An early-season blizzard over parts of the Rocky Mountain west.
Severe Weather/Tornado Outbreak
A major severe weather outbreak is expected to occur over parts of the upper Midwest during the day on Friday as a result of the warm front that extends from the low pressure system over the central Plains.
The Storm Prediction Center has issued a moderate risk for severe weather for the area:
And they've issued the following probabilities for severe weather during the day on Friday. A 45% shaded area means that there is a 45% chance of any type of severe weather (a tornado, large hail, and/or damaging winds) within 25 miles of any point within the shaded area. The black hatching indicates the risk for significant severe weather (an EF-2 or stronger tornado, hail larger than golf balls, and/or damaging winds in excess of 75 MPH).
The warm front over the area is expected to serve as a focal point for severe weather to form. All modes of severe weather (hail, wind, and tornadoes) are possible, with the SPC specifically mentioning that a couple of strong tornadoes are possible.
2) Tropical Storm (Hurricane?) Karen
Tropical Storm Karen is churning in the Gulf of Mexico at this hour with 65 MPH winds as it moves generally northward towards the northern Gulf Coast. The forecast track from the National Hurricane Center takes Karen ashore in southern Alabama -- near Mobile (where I am) -- on Saturday night as a strong tropical storm.
The system is expected to briefly attain hurricane status sometime during the day on Friday before weakening again due to cooler waters and the effects of wind shear.
Accordingly, a hurricane watch is in effect for parts of southeastern Louisiana, southern Mississippi, southern Alabama, and the western Florida Panhandle. A tropical storm warning is in effect for parts of southeastern Louisiana.
The effects of Karen will mostly be limited to very heavy rainfall and gusty winds. Over 6 inches of rain are possible across parts of the northern Gulf Coast as it approaches on Saturday -- the key to the heavy rain is which side of the storm the heaviest precipitation. As the remnants of the system move and the cold front catches up with it, the system will begin to move over the southeast and Mid-Atlantic during the day on Sunday and into Monday.
An early-season blizzard is anticipated over parts of the Rockies and upper Plains on the back end of the low pressure system, where very cold air from Canada is streaming down into the region. Winter storm warnings are in effect for a large portion of the area expected to receive snowfall, and a blizzard warning is in effect for western parts of South Dakota.
Over a foot of snow is possible across a wide stretch of the northern Rockies and upper Plains, with locally higher amounts approaching two feet.
The most dangerous part of this winter storm are the expected winds. Areas under the blizzard warning (the counties shaded in red) can expect around a foot of snow accompanied by wind gusts over 70 MPH. The combination of heavy snow and extremely strong winds is lethal -- people outdoors during the blizzard can quickly become disoriented due to the whiteout conditions.
Rapid City and Sturgis in western South Dakota are included in the blizzard warning.
It's important to note that the National Weather Service is operational during the Federal government shutdown. Your dedicated forecasters at the NWS are going to work just as hard as they always have, just without pay. Forecasting services should not be affected by the tantrum over in the House of Petulance. When things calm down, be sure to go to your local NWS office's website and send them a thank you note.
You can follow the latest forecasts for Karen, the severe weather, and the blizzard over at the National Weather Service's website, as well as the National Hurricane Center and the Storm Prediction Center.
I'm in Mobile, AL, which looks like it's going to take a direct hit from Tropical Storm Karen on Saturday. I'm rarely in the middle of a big weather event, so I'll probably take lots of pictures and videos to document the storm as it happens.
I might not be able to keep a severe weather liveblog going during the day tomorrow as I have classes, but I'll do my best if violent tornadoes start forming.
3:42 PM PT: Note: The blizzard does not have a name. Blizzards are not named. Ignore The Weather Channel's savvy social media advertising campaign, and don't feed into it.